Buzzing, hissing

[benaolson]

Anyone else having problems with their time factor having apparent shielding problems plus major hiss out of nowhere? I used my time factor virtually noise free for about a year or so, and then all of the sudden I get major hiss, plus sporadic electric buzzing. I also get major buzzing if the USB is plugged into my Macbook Pro.

Any idea if this is a common problem?

[nickrose]

You may well get get buzzing when the USB is plugged in if this causes a ground loop.

No instant solution – ground loops have to be cured on a one-by-one basis. In this case, running your Mac with the charger disconnected might do it.

[badmelonfarmer]

Have you changed your Amp recently?

I have seen peeople complaining about TimeFactor noise….but it seemed to be more related to a speciffic Amp(s) they were using rather than a fault with the TimeFactor.

there was a lot of posts around one speciffic issue and it turned out to be the Cheiftain Amp… edit … based on his comments a few posts down Andy seems to be suggesting it was more pickup related. Although my pickups are all 'Vintage style' and not high output by any stretch.

[benaolson]

I play keys, and I have my pedalboard actually running into my laptop before going out to any amps. I have tried running the TimeFactor without the interface for the laptop direct into every amp I own, and it's the same problem all around sadly.

[benaolson]

nickrose:

You may well get get buzzing when the USB is plugged in if this causes a ground loop.

No instant solution – ground loops have to be cured on a one-by-one basis. In this case, running your Mac with the charger disconnected might do it.

I get the buzzing without having the usb hooked up on occasion as
well….is that still going to be related to the way I am powering
everything in my rig? It does seem that the Macbook power can exacerbate the noise when it is brought too close to my pedalboard power, but I figured that was just the electric field, which shouldn't be a problem from a distance?

Just for reference, I power the TimeFactor from the power supply that came with it which I put on a power strip that is hooked up to a Pedal Power Plus, which is usually just plugged into the main power wherever I'm at via extension chord (legitimate clubs that have lighting and such on separate circuits and whatnot…I obviously know nothing about power). I also have a power strip for a small rack I have (generally just a compressor and audio interface for my laptop). I also have the Macbook, which is just run to the main power as well.

[parsky1]

The places to start looking is where you are using 3-prong plugs.  Generally, 2 prong supplies like wallwarts don't have the the secondary side ground of the transformer tied to AC ground (output is floating).  When I speak of "AC Ground" I'm speaking of the green wire in household wiring.  The reason why we love those Fat walwarts is because the transformer has 4000 volts of isolation and therefore there is almost a zero chance of a short from the primary to secondary side.  In the case of switching power supplies (3 prong type like those with laptops, televisions, etc) it is difficult to obtain 4000 volt isolation because these supplies have very high switching frequencies which usually have smaller transformers with lower primary to secondary isolation.  If there is a short between primary to secondary, then it gets shorted to ground and trips a fuse.  Saving you from an unpleasant shock or death.

I would usually start looking for 3-prong type adapters.  Most amps, as far as I can tell, have the secondary side ground tied to AC ground just like laptop supplies.  Therefore if you want zero hum you can' thave any other supplies that are wired this way.  That is why I put every effect on its own FAT walwart (none of those junky switching walwarts) or each on a separate output of a Pedal Power 2+, Cioks DC10, or PowerFactor.   

You could also buy an Ebtech Humx which basically uses an old back to back diode trick to tie the secondary side ground to ac ground.  Basically in normal operation the diodes prevent the "hum" current from flowing.  If there is a primary to secondary side short, the secondary side voltage exceeds the 0.7V drop of the diode and it begins to conduct thus blowing the fuse and protecting you from getting shocked. 

You can try diagnosing with a 2-prong "cheater" plug, but this is at your own risk and I would not use it as a long term solution.  It may at least tell you where you have a ground loop.  This is at your own risk and I take no responsibility for it.

My suspicion is that both the amplifier and macbook are the sources of the ground loop and one of those needs to get lifted.  Basically some of the ground current from your amp with a slight 60hz component on it is not going back to its original ground as it going through the audiopath ground to your macbook, or viceversa.   It could also be the fact that you have other FX pedals daisy chained to the same supply.  Usually what happens is there has always been a ground loop but as people add more fx pedals the problem becomes amplified due to various reasons.

 I have also seen it where the shell of a patch cable is touching the metal of your pedalboard and causing a hum.  This is probably because the chasis of my Voodoo labs pedal power is tied to AC ground and since it is screwed into the pedalboard, it ties the entire pedalboard chasis to AC ground.  Therefore whenever the metal plug of a patch cable touches it, some AC current flows through the patchcable shield.  If this is on a cable on the input side of a guitar amp and you run a high gain channel you will definately notice it.

Also, whenever possible, plug your pedalboard and amp into the same outlet.  Actually just always do this to lessen the chances of hum issues.

[aothling]

Just so you know, this is incorrect. I was the one with that problem, and it was not the amp. Lots of other people have the problem with different amps. The problem stems from the fact that the Timefactor requires a certain amount of input volume that my guitars couldn't supply (low-output single coils), so the signal to noise ratio was a little too low, and it introduced noise.

[aothling]

Sorry. I was trying to quote badmelonfarmers post above.

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